I had the opportunity to fly Dick Carville's Sieverling Mustang yesterday, over in Wrentham, MA.  WOW!  This ship flies incredibly well!  Dick is a superb builder, which certainly helps.  The P-51 was one of those special stunt ships that is easy to pull through the pattern.  Dick built the plane from plans, and put in a ST 46 to help it along.  What a really nice combination!  Hope someone who was there will post a photo; Dick is an excellent finisher as well.